The function of Animal Shared Resource (ASR) is to facilitate the efficient, economical, and state-of-art use of animal models for the performance of cancer-related studies. This is accomplished through a centralized resource, where AALAS-certified veterinary technicians/technologists provide high-quality research services to Lombardi members. A significant emphasis is placed on the use of genetically modified mice, athymic mice, and zebrafish. Major services provided include coordination of animal and special animal feed purchase requests; performance of specific manipulations, including diet, hormone or drug administrations to modify tumor initiation, promotion, progression or metastasis; inoculation of tumor cells or in vivo propagation of tumor cell lines in animals; administration of carcinogens; monitoring tumor growth; collection of tumors, organs, and sera; performance of necropsies and biopsies; and zebrafish studies, including microinjecting eggs with antisense Morpholino oligonucleotides (MO) to knock down specific genes of interest; microinjecting eggs with RNA or cDNA to overexpress wild-type, mutant and chimeric genes; screening for toxicity/drugs; generating transgenic zebrafish; transplanting cells; and xenotransplantation experiments. The ASR is located within Georgetown University Medical School's Division of Comparative Medicine (DCM). The DCM is a centralized, AAALAC-accredited, USDA-registered animal facility and has an approved letter of assurance on file at the NIH. The general environment and animal health is monitored through the use of sentinel mice maintained on each rack in each animal room as part of a comprehensive health surveillance program. All immune-deficient rodents are maintained within a Specific Pathogen Free environment. Most genetically modified mice colonies are maintained in a dedicated barrier isolation facility. The services of this resource are critical for the Lombardi investigators who perform preclinical studies to test hypotheses related to treatment and prevention of cancer using state-of-art, and appropriate, effective and economical animal models. The highly trained and experienced technical staff works closely with Lombardi members to provide quality animal model technical services in support of peer reviewed cancer research requiring the use of animals. In 2008, these services were used in support of peer-reviewed projects of 18 Lombardi members in five Cancer Center Programs.